1. Field of the Invention
The present invention relates generally to semiconductor technology, and more particularly to a method for processing a glass substrate.
2. Description of Prior Art
Recently, Resistance Random Access Memory (RRAM) has been recently studied as a next generation non-volatile memory because of its characteristics, such as simple structure, low power, high-speed, and compatibility with modern semiconductor CMOS processing. During the research of RRAM materials, researchers have found multiple material systems that may be used for RRAM. Those multiple material systems may include rare MnSiOx materials, transition perovskite-type materials, binary transition metal oxides, organic macromolecular semiconductor materials, and some sulfide materials. Currently, the research on binary transition metal oxides mainly includes NiO, TiOx, CuxO, Cu—MoOx, ZnO, Mg—ZnO, Co—Zno, Mn—ZnO, Fe2O3, ZrO2, and the like.
Since binary transition metal oxides generally have a large optical energy gap >3eV, they have good transmittance in the visible light range. Therefore, if a transparent electrode substrate is selected for their manufacture, it would be possible to achieve the fabrication of a transparent RRAM storage unit, which could also be integrated to optically transmissive electronic devices for the future. This transparent RRAM device would not be a substitute for the current semiconductor-based electrode devices, but may provide a new concept and trend for future optically transmissive electronic devices that may be widely used in the field of transparent electronic devices.
The fabrication of RRAM, including binary transition metal oxides, may require a transparent glass substrate. On the substrate, a sandwich of electrode layer/binary transition metal oxide layer/electrode layers is fabricated, forming a part of the structure of a RRAM storage unit. The electrode layer has high conductivity (or resistivity in the range of 10−5˜10−4 Ω/cm). The binary transition metal oxide layer possesses resistance transformation characteristics, which are useful for memory storage, and also possesses high transmittance for visible light.
The glass substrate in RRAM is transparent and non-conductive. However, current substrate transport hardware in some semiconductor tools may properly work with only opaque or conductive semiconductor substrates. Therefore, current substrate transport hardware in some semiconductor tools may not recognize glass substrates nor transport them properly between process chambers to perform processes like litho, thin film, diffusion, and etching. Therefore, there is a need to solve the fabrication difficulties for RRAM with a glass substrate.